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# 1 : : // Copyright (c) 2018-2021 The Bitcoin Core developers
# 2 : : // Distributed under the MIT software license, see the accompanying
# 3 : : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
# 4 : :
# 5 : : #ifndef BITCOIN_SCRIPT_DESCRIPTOR_H
# 6 : : #define BITCOIN_SCRIPT_DESCRIPTOR_H
# 7 : :
# 8 : : #include <outputtype.h>
# 9 : : #include <script/script.h>
# 10 : : #include <script/sign.h>
# 11 : : #include <script/signingprovider.h>
# 12 : :
# 13 : : #include <optional>
# 14 : : #include <vector>
# 15 : :
# 16 : : using ExtPubKeyMap = std::unordered_map<uint32_t, CExtPubKey>;
# 17 : :
# 18 : : /** Cache for single descriptor's derived extended pubkeys */
# 19 : : class DescriptorCache {
# 20 : : private:
# 21 : : /** Map key expression index -> map of (key derivation index -> xpub) */
# 22 : : std::unordered_map<uint32_t, ExtPubKeyMap> m_derived_xpubs;
# 23 : : /** Map key expression index -> parent xpub */
# 24 : : ExtPubKeyMap m_parent_xpubs;
# 25 : : /** Map key expression index -> last hardened xpub */
# 26 : : ExtPubKeyMap m_last_hardened_xpubs;
# 27 : :
# 28 : : public:
# 29 : : /** Cache a parent xpub
# 30 : : *
# 31 : : * @param[in] key_exp_pos Position of the key expression within the descriptor
# 32 : : * @param[in] xpub The CExtPubKey to cache
# 33 : : */
# 34 : : void CacheParentExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub);
# 35 : : /** Retrieve a cached parent xpub
# 36 : : *
# 37 : : * @param[in] key_exp_pos Position of the key expression within the descriptor
# 38 : : * @param[in] xpub The CExtPubKey to get from cache
# 39 : : */
# 40 : : bool GetCachedParentExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const;
# 41 : : /** Cache an xpub derived at an index
# 42 : : *
# 43 : : * @param[in] key_exp_pos Position of the key expression within the descriptor
# 44 : : * @param[in] der_index Derivation index of the xpub
# 45 : : * @param[in] xpub The CExtPubKey to cache
# 46 : : */
# 47 : : void CacheDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, const CExtPubKey& xpub);
# 48 : : /** Retrieve a cached xpub derived at an index
# 49 : : *
# 50 : : * @param[in] key_exp_pos Position of the key expression within the descriptor
# 51 : : * @param[in] der_index Derivation index of the xpub
# 52 : : * @param[in] xpub The CExtPubKey to get from cache
# 53 : : */
# 54 : : bool GetCachedDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, CExtPubKey& xpub) const;
# 55 : : /** Cache a last hardened xpub
# 56 : : *
# 57 : : * @param[in] key_exp_pos Position of the key expression within the descriptor
# 58 : : * @param[in] xpub The CExtPubKey to cache
# 59 : : */
# 60 : : void CacheLastHardenedExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub);
# 61 : : /** Retrieve a cached last hardened xpub
# 62 : : *
# 63 : : * @param[in] key_exp_pos Position of the key expression within the descriptor
# 64 : : * @param[in] xpub The CExtPubKey to get from cache
# 65 : : */
# 66 : : bool GetCachedLastHardenedExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const;
# 67 : :
# 68 : : /** Retrieve all cached parent xpubs */
# 69 : : const ExtPubKeyMap GetCachedParentExtPubKeys() const;
# 70 : : /** Retrieve all cached derived xpubs */
# 71 : : const std::unordered_map<uint32_t, ExtPubKeyMap> GetCachedDerivedExtPubKeys() const;
# 72 : : /** Retrieve all cached last hardened xpubs */
# 73 : : const ExtPubKeyMap GetCachedLastHardenedExtPubKeys() const;
# 74 : :
# 75 : : /** Combine another DescriptorCache into this one.
# 76 : : * Returns a cache containing the items from the other cache unknown to current cache
# 77 : : */
# 78 : : DescriptorCache MergeAndDiff(const DescriptorCache& other);
# 79 : : };
# 80 : :
# 81 : : /** \brief Interface for parsed descriptor objects.
# 82 : : *
# 83 : : * Descriptors are strings that describe a set of scriptPubKeys, together with
# 84 : : * all information necessary to solve them. By combining all information into
# 85 : : * one, they avoid the need to separately import keys and scripts.
# 86 : : *
# 87 : : * Descriptors may be ranged, which occurs when the public keys inside are
# 88 : : * specified in the form of HD chains (xpubs).
# 89 : : *
# 90 : : * Descriptors always represent public information - public keys and scripts -
# 91 : : * but in cases where private keys need to be conveyed along with a descriptor,
# 92 : : * they can be included inside by changing public keys to private keys (WIF
# 93 : : * format), and changing xpubs by xprvs.
# 94 : : *
# 95 : : * Reference documentation about the descriptor language can be found in
# 96 : : * doc/descriptors.md.
# 97 : : */
# 98 : : struct Descriptor {
# 99 : 233791 : virtual ~Descriptor() = default;
# 100 : :
# 101 : : /** Whether the expansion of this descriptor depends on the position. */
# 102 : : virtual bool IsRange() const = 0;
# 103 : :
# 104 : : /** Whether this descriptor has all information about signing ignoring lack of private keys.
# 105 : : * This is true for all descriptors except ones that use `raw` or `addr` constructions. */
# 106 : : virtual bool IsSolvable() const = 0;
# 107 : :
# 108 : : /** Convert the descriptor back to a string, undoing parsing. */
# 109 : : virtual std::string ToString() const = 0;
# 110 : :
# 111 : : /** Whether this descriptor will return one scriptPubKey or multiple (aka is or is not combo) */
# 112 : : virtual bool IsSingleType() const = 0;
# 113 : :
# 114 : : /** Convert the descriptor to a private string. This fails if the provided provider does not have the relevant private keys. */
# 115 : : virtual bool ToPrivateString(const SigningProvider& provider, std::string& out) const = 0;
# 116 : :
# 117 : : /** Convert the descriptor to a normalized string. Normalized descriptors have the xpub at the last hardened step. This fails if the provided provider does not have the private keys to derive that xpub. */
# 118 : : virtual bool ToNormalizedString(const SigningProvider& provider, std::string& out, const DescriptorCache* cache = nullptr) const = 0;
# 119 : :
# 120 : : /** Expand a descriptor at a specified position.
# 121 : : *
# 122 : : * @param[in] pos The position at which to expand the descriptor. If IsRange() is false, this is ignored.
# 123 : : * @param[in] provider The provider to query for private keys in case of hardened derivation.
# 124 : : * @param[out] output_scripts The expanded scriptPubKeys.
# 125 : : * @param[out] out Scripts and public keys necessary for solving the expanded scriptPubKeys (may be equal to `provider`).
# 126 : : * @param[out] write_cache Cache data necessary to evaluate the descriptor at this point without access to private keys.
# 127 : : */
# 128 : : virtual bool Expand(int pos, const SigningProvider& provider, std::vector<CScript>& output_scripts, FlatSigningProvider& out, DescriptorCache* write_cache = nullptr) const = 0;
# 129 : :
# 130 : : /** Expand a descriptor at a specified position using cached expansion data.
# 131 : : *
# 132 : : * @param[in] pos The position at which to expand the descriptor. If IsRange() is false, this is ignored.
# 133 : : * @param[in] read_cache Cached expansion data.
# 134 : : * @param[out] output_scripts The expanded scriptPubKeys.
# 135 : : * @param[out] out Scripts and public keys necessary for solving the expanded scriptPubKeys (may be equal to `provider`).
# 136 : : */
# 137 : : virtual bool ExpandFromCache(int pos, const DescriptorCache& read_cache, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const = 0;
# 138 : :
# 139 : : /** Expand the private key for a descriptor at a specified position, if possible.
# 140 : : *
# 141 : : * @param[in] pos The position at which to expand the descriptor. If IsRange() is false, this is ignored.
# 142 : : * @param[in] provider The provider to query for the private keys.
# 143 : : * @param[out] out Any private keys available for the specified `pos`.
# 144 : : */
# 145 : : virtual void ExpandPrivate(int pos, const SigningProvider& provider, FlatSigningProvider& out) const = 0;
# 146 : :
# 147 : : /** @return The OutputType of the scriptPubKey(s) produced by this descriptor. Or nullopt if indeterminate (multiple or none) */
# 148 : : virtual std::optional<OutputType> GetOutputType() const = 0;
# 149 : : };
# 150 : :
# 151 : : /** Parse a `descriptor` string. Included private keys are put in `out`.
# 152 : : *
# 153 : : * If the descriptor has a checksum, it must be valid. If `require_checksum`
# 154 : : * is set, the checksum is mandatory - otherwise it is optional.
# 155 : : *
# 156 : : * If a parse error occurs, or the checksum is missing/invalid, or anything
# 157 : : * else is wrong, `nullptr` is returned.
# 158 : : */
# 159 : : std::unique_ptr<Descriptor> Parse(const std::string& descriptor, FlatSigningProvider& out, std::string& error, bool require_checksum = false);
# 160 : :
# 161 : : /** Get the checksum for a `descriptor`.
# 162 : : *
# 163 : : * - If it already has one, and it is correct, return the checksum in the input.
# 164 : : * - If it already has one that is wrong, return "".
# 165 : : * - If it does not already have one, return the checksum that would need to be added.
# 166 : : */
# 167 : : std::string GetDescriptorChecksum(const std::string& descriptor);
# 168 : :
# 169 : : /** Find a descriptor for the specified `script`, using information from `provider` where possible.
# 170 : : *
# 171 : : * A non-ranged descriptor which only generates the specified script will be returned in all
# 172 : : * circumstances.
# 173 : : *
# 174 : : * For public keys with key origin information, this information will be preserved in the returned
# 175 : : * descriptor.
# 176 : : *
# 177 : : * - If all information for solving `script` is present in `provider`, a descriptor will be returned
# 178 : : * which is IsSolvable() and encapsulates said information.
# 179 : : * - Failing that, if `script` corresponds to a known address type, an "addr()" descriptor will be
# 180 : : * returned (which is not IsSolvable()).
# 181 : : * - Failing that, a "raw()" descriptor is returned.
# 182 : : */
# 183 : : std::unique_ptr<Descriptor> InferDescriptor(const CScript& script, const SigningProvider& provider);
# 184 : :
# 185 : : #endif // BITCOIN_SCRIPT_DESCRIPTOR_H
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